1. Field of the Invention
This invention relates to an electrical connector and more particularly relates to means for retaining a properly seated terminal within an electrical connector and means for maintaining the electrical connector in a fully mated position relative to a mating connector.
2. Description of the Prior Art
The improper installation of electrical connectors has long been a problem in assemblies containing large numbers of interconnected electrical circuits. Even though the specific electrical connector can perform adequately under normal circumstances, opens can occur when terminals are not properly positioned within electrical connector insulative housing and when mating electrical connectors are not properly mated. In addition to opens which result from improper installation, terminal and connector retention are also important because of the problems that can be encountered over the life of the particular device. For example excessive vibration can cause one connector to become disengaged from another connector. Furthermore, improper retention of contact terminals and connectors can result in unstable electrical interfaces which can result in corrosion thus leading to a gradual deterioration of the electrical interconnection.
A number of steps have been taken to improve the retention of contact terminals within electrical connectors and the mating integrity between two electrical connectors. For example plastic terminal latches or lances which comprise an integral part of an insulative housing are often used to retain terminals within the housing. These plastic terminal latches replace the metal latches on the contact terminals themselves which have been commonly used for a number of years. One problem with these metal latches is that they can easily be overstressed during terminal insertion resulting in significantly reduced in retention of pull-out capability. Furthermore these metal latches have caused problems in the installation of electrical harnesses since the promote tangling of the harnesses. In addition to the use of plastic terminal latches which comprise an integral part of the insulative housing, it is now common practice to use secondary retention members which also lock terminals in place. Typically these secondary locks comprise a separate member which is inserted into the plastic insulative housing and engage a surface on the terminal to provide additional retention. Certain secondary locking members not only independently lock a terminal in position but can only be attached to the electrical connector if the terminal is in the fully inserted position. In addition certain inserts not only independently lock the terminal in place but also move an improperly seated terminal into its fully seated position. These inserts have been referred to as terminal position assurance inserts (TPA). In addition to auxiliary inserts used for terminal position assurance, separate inserts have also been used to hold two mated connectors in engagement. For example U.S. Pat. No. 4,746,306 discloses an electrical connector in which a pin is inserted into engagement with a resilient latch to prevent that resilient latch from becoming dislodged from a mating latch member on a mating connector. Auxiliary devices can be referred to as connector position assurance inserts (CPA). Although CPAs and TPAs do help to assure that a reliable electrical interconnection can be established and maintained, they do represent additional components which must be assembled to the electrical connectors.
At the same time that additional components have been added to electrical connectors to insure that a reliable electrical interconnection is established and is maintained, there has been an increase in the number of electrical circuits which must be fitted within a defined space. This trend has been accelerated by the increasing use of solid state electrical components. U.S. Pat. No. 4,722,704 discloses a high density socket contact receptacle intended for use with a pin header. This electrical connector provides a high density interconnect between wires of a harness and circuits on a printed circuit board. That connector includes both integral plastic latches forming a part of the insulative housing and a separate TPA. No CPA insert is employed.
The instant invention comprises not only high density connector but also employs resilient plastic terminal latches comprising integral part of the instant housing, a TPA insert and CPA insert. Furthermore the instant invention employs a one-piece member which serves both as a TPA insert for one row of terminals and a CPA insert. All this is accomplished in a connector in which adjacent terminals are spaced apart on center lines of 3.0 mm.